How to implement a one time authentication mechanism? - authentication

I'm trying to create a website to authenticate users through the use of a throwaway password where the assumption is that the user might not use the website again (basically a one time access).
I have done my research on OTP and various solutions to authentication but these don't seem to fit my requirements, most of them seem to rely on users having login credentials to the website whereas my system would allow them access without the need for registering.

The implementation of passwordless authentication by Auth0 seems to fit what you're describing. Even if you were not considering a third-party provider it may be useful to go through the documentation.
Basically, a user can login to a site without any need for a sign-up process. They can do so just by requesting that a one time code is delivered to them, for example, either by email or SMS.
This way, they can get quick access without having to setup a user and in the event that they do come back your application can recognize this because they will most likely be using the same mechanism, that is, you can use the email or mobile phone as the unique identifier.
Disclosure: I'm an Auth0 engineer.

If you do not require your users to register, why do you need authentication at all?
Why not just set a cookie with an unique identifier on the first visit? You can store data at the server side associated with that identifier. Keep track of when you last saw the user, and if they do not return within a certain period, you can delete any data you stored for that user.

Related

Database structure for multiple authentication sources of users in a web app

I'm trying to work out how to structure a database schema that allows me to have multiple authentication sources for the same end-user.
For example, my web app would require users to sign in to utilize many of the functionality of features of the app. However, I do not want to be responsible for storing and authenticating user passwords.
I would like to outsource this responsibility to Google, Facebook, Twitter and similar identity providers.
So I would still need a database table of users, but no column for a password. However, these are authenticated would not be my concern. But I would still need to somehow associate my user with the identity providers user id. For example, if my user signs up with Google, I would store the users Google ID and associate this with my user. Meaning next time the user makes an attempt to login and is successfully authenticated at Google, I would make an attempt to find any user in my system that has this associated user id.
I've been trying to look for some common and recommended database structures, with no luck. Maybe I'm searching for the wrong terms for this because I cannot imagine that this is an uncommon way to do it. StackOverflow seems to do something similar.
The way I imagine it, it would allow me to associated multiple authentication sources for one app user. Meaning once I've signed up with Google, I can go to my settings and associate another account, for example, a Facebook account.
How should I go about achieving this in a flexible and clean way?
Thanks.
You need to know what data you have to save in your db to authenticate a user with a third party login.
For example, once I used Google to login users in my app, I save Google user id first time a user logs in and get data the next time.
You could have an entity with third party providers, so you will create a table with 2 values, user_id (your user data) and provider_id (Google, facebook, twitter...).
If you are going to use just one provider then you could add provider_id field to your users table.

Devise: Migrate Google Open ID to Google OAuth

Does anyone have clues about how to do this? I'm basically trying to replace the strategy for "Connect With Google" from OpenID to OAuth. The challenge is identifying an old user (user on Google open ID) when a user signs in under the new OAuth scheme.
I have a working implementation which relies on email address as the primary key, as the open ID strategy captures that. The problem is, I don't want to ask for email in the OAuth flow. The ideal value is simply Google user ID, but the Open ID strategy doesn't seem to capture that.
So I have open ID tokens like https://www.google.com/accounts/o8/id?id=AfSCwGQ4PUaidXSQddJugXKLqU5V0MrXFhJM6UHybPw and trying to understand if I could get a Google ID from that.
UPDATE: I explained here how I ended up doing this migration - http://softwareas.com/migrating-user-accounts-from-google-openid-to-google-oauth-to-google-plus
We don't have a strategy ready today that avoids the user seeing another approval page.
However, rather than attempt to do an OAuth1 based hybrid flow and have to add all that legacy code to your server, I'd suggest you simply correlate on email address and move to OAuth2 login. I'm assuming you're like the majority of sites that end up asking for email address because they usually want it for account recovery. Just make sure you get the email address from OpenId as one of the signed parameters.
Then use the userinfo.email scope and OAuth2 https://developers.google.com/accounts/docs/OAuth2Login and you should be able to migrate with less developer pain.
In addition, we're in the process of adding support for OpenIDConnect and it supports a parameter of login_hint so you'd add &login_hint=bob#gmail.com to your authorization URL and it will steer the approval to the right account. This is not documented right now but it may be useful for you to try it. The user's browser could be logged into Google with a number of accounts and you want to try to get the right one. Always check the email you get from the OAuth2 flow to make sure it matches since this is just a 'hint'.
Users will still have to re-authorize for OAuth2, but we have plans to skip this reauthorization in the future. The main point is to plan on using OAuth2 and we hope to deliver a seamless migration soon and you'll be on a supported protocol.
Google uses directed identifiers for OpenID that are unique per relying party and are explicitly designed to conceal any correlatable identifier for the user. So the short answer is, no there's no way to get a Google ID that corresponds with a given Google OpenID.
One option, however, might be to use Google's OpenID+OAuth Hybrid flow. This allows you to get an OAuth token as part of a normal OpenID flow, which could then be used to get the user's ID from the OAuth2 Login API, which you can then associate with their existing account. Once you've done that for all of your existing users, then switch to using the OAuth2 Login directly.
The trick, of course, with this approach is getting all of your users to login again so that you can send them through the new flow. That will come down to how long you're willing to wait to migrate accounts, and whether you're willing to prod existing users by emailing them and asking them to login again (similar to a forced password reset).

Alternative user registration/authorization methods?

All I want is a persistent membership system and easy registration/login process for my several social applications.
I don't really need their e-mail addresses or personal information.
However, I don't want to convert my websites into an anonymous board or spamming area for bots, etc. and I don't want to force my visitors to login through their Facebook or Google accounts.
What do you recommend in this case?
Thanks.
You can't have it both ways. Either you want an anonymous site or you need some type of authentication/identification.
There are several easy options for authentication.
E-mail only. You can do authentication with e-mail only and cookies, no password. This isn't common and is often used in addition to passwords for high-security scenarios, but can be used without passwords for even simpler security. Basically have users log-in with their e-mail only. Then send them a confirmation mail and they click a link in the confirmation mail. When they click the link, store a permanent cookie and from then on they're authenticated. If they loose the cookie, they can repeat the process and authenticate again with the same e-mail address. No manual account creation, no passwords. It's really just as or even more secure than using a password. It's a little cumbersome though to get an e-mail to login, but hopefully cookies will not be lost. Several of my banking/credit card companies do this in addition to e-mail and the only time I notice is when I change computers.
E-mail/password. Don't downplay the usefulness and simplicity of a email/password authentication. Users are accustomed to id and it works fine. As long as you have it isolated to a single small form to create an account, it won't really get in the way.
OpenID. I believe all public website should support OpenID as an available authentication mechanism. For people and sites that use it, it's wonderful. Simple authentication and easy to use. Setup is painful for people that don't know what it is or how to use it, so I wouldn't recommend using OpenID only except for techie sites, but it's a great alternative.
I'd suggest you to use OpenID authentication on your website. This way, you need not to worry about the hassles of storing and retreiving user data on your server plus offer the facility to user to use thier OpenID login credentials for your website.
Kimd regards,
Dorcy

Can OpenID be used to authenticate access to a website client area?

Is it possible to limit the users who can sign in with open id on my site. I have clients that I want to give access to a client area on my website. I don't want anyone with a open id to be able to login just my clients. Is this possible?
One way to do this would be to create a "sign up" form to validate the user. Part of the sign up process would be to associate your OpenID. You can then leave the newly created account in a "pending" mode to be approved by an admin. (note: if you have a different way of adding the clients, you would use that method.)
Basically you would create a profile for a user the same way you would in any other application, except you would replace the UserName / Password portion with OpenID.
OpenID is made for authentification, not for authorization. I am sure, you could make it work (*), however you must keep in mind that OpenID has not been made for this sort of task.
If you want to do it, you must probably restrict the set of allowed OpenID providers to prevent a malicious provider to hand faked/bogus identity URLs to your application (consumer).
(*) how, depends on where you want to enforce the restriction (web server, web framework, etc.)

is openid.claimed_id static?

I'm reading about Federated Login for Google Account Users to figure out how I can have a user log in to a web application using their Google Account.
So towards the end of the process, Google returns a Google supplied identifier which is appended as openid.claimed_id. This means the web application uses this identifier to recognize the user and allow access to application features and data. My question is, is this identifier static? Can I use this identifier to repeatedly id the same user?
Yes. Consider the openid.claimed_id value to be the username. Especially with Google, but this is true for any OpenID Provider that truly implements 'directed identity', don't consider this username to be correlatible with other web sites. Any other relying party besides your own web site will get a different claimed_id value for the same Google user, by design.
Also, be sure to treat this claimed_id as case sensitive.
The specific answer to your question is found in Googles OpenID API documentation:
The Google-supplied identifier, which has no connection to the user's actual Google account name or password, is a persistent value; it remains constant even if the user changes their Google user name and/or email address. This identifier is also a "directed identity", that is, Google returns a different value to each relying party. Google uses the request parameter openid.realm to recognize the relying party, so if the third-party application decides to change this value, all user identifiers will change.
In fact, I just ran into an instance where the google claimed_id had changed for my test user. I was coming to the end of implementing OpenID into my app, and for no apparently reason the claimed_id in the response data is had changed.
I've been testing with this account for the past couple weeks, and the claimed_id was the same this entire time, as expected. Then wham, changed! I looked at the response data many times to verify, and the underlying code to retrieve the data had not changed.
I'm not sure how to handle this at the moment, but I think this is going to throw me for a loop. After initial authentication, users register to the site (as you might expect) and setup a screen name. How are we to verify it is the same user if the claimed_id had changed? We certainly can't use email address, per best practices.
EDIT
Now I have pie in my face! I missed one little detail, that turned out to be a major detail. I change my development environment and was hosting on a different v-host. This effectively change the realm, and this will change the claimed_id response according to the docs.
This was a good lesson for me, as I was about to implement OID on a subdomain in which realm was being set automatically in my code. Now I saved myself a headache down the road, because I would not have been able to use the same user database across all other sub-domains without breaking identity.
updating realm
MORE INFO
Just as a side note - even if you are developing your OpenID solution for one of your subdomains, it might be prudent for you to specify realm to your top-level domain.
e.g., openid.realm = http://*.yourdomain.com
It will allow you to expand your sign-in page across all your subdomains and keep user identity across them.
(optional) Authenticated realm. Identifies the domain that the end
user is being asked to trust. (Example: "http://*.myexamplesite.com")
This value must be consistent with the domain defined in
openid.return_to. If this parameter is not defined, Google will use
the URL referenced in openid.return_to.